There has long been a need, by the owners of pick-up trucks, for a simple, inexpensive ramp, free from mechanical difficulties. The transportation of snowmobiles, three wheelers, and other heavy items are common occurrences for the owners of pick-up trucks. Consequently, a retractable ramp operable by a single person is a useful improvement for those people who desire to transport heavy articles. Moreover, it is desirable to minimize the modifications necessary to provide a pick-up truck with a ramp.
U.S. Pat. No. 3,870,170 issued to Noble, Mar. 11, 1975, and entitled: "Loading Ramp for Pick-Up Trucks and the Like" teaches a raised platform in a complex design comprising fixed tracks, movable tracks, a gang plank and rollers. Noble's movable tracks provide a continuous horizontal trackway from the front end of the ramp storage compartment to the rear edge of an opened tailgate. Both Noble's ramp and movable tracks can be retracted far enough so that both the ramp door at the rear end of the raised platform assembly, and the tailgate, may be closed to preserve the exterior appearance of the pick-up truck.
The Noble disclosure does not, however, purport to teach a low-cost ramp for non-commercial use by owners of pick-up trucks, station wagons, etc. Noble's movable tracks and rollers are designed to handle heavy industrial and commercial cargo.